Treatment depends on the person’s general health and how severely malnourished they are.

The first dietary advice is usually:

eating "fortified" foods that are high in calories and protein

snacking between meals

having drinks that contain lots of calories

Some people also need support to help with underlying issues such as limited mobility – for example, care at home or occupational therapy. If a child is malnourished, their family may need advice and support to address the underlying reasons why this may have happened..

If these initial dietary changes aren't enough, a doctor, nurse or dietitian may also suggest taking extra nutrients in the form of nutritional drinks or supplements.

If the person has difficulty eating that can't be managed by making changes such as eating soft or liquid food, other treatments may be recommended, such as:

a feeding tube – this can be either passed down the nose and into the stomach, or inserted directly into the stomach through the skin of the tummy

You can also become malnourished if your body needs an increased amount of energy – for example, if it's healing after surgery or a serious injury such as a burn, or if you have involuntary movements such as a tremor.

Medicines

Some types of medication may increase your risk of developing malnutrition.

Some medicines have unpleasant side effects – such as loss of appetite, diarrhoea or nausea – that could mean you eat less or don't absorb as many nutrients from your food.

Physical and social factors

The following factors can also contribute to malnutrition:

teeth that are in a poor condition, or dentures that don't fit properly, which can make eating difficult or painful

a physical disability or other impairment that makes it difficult to move around, cook or shop for food

living alone and being socially isolated

having limited knowledge about nutrition or cooking

alcohol or drug dependency

low income or poverty

Causes of malnutrition in children

In the UK, malnutrition in children is commonly caused by long-term health conditions that:

Some children may become malnourished because of an eating disorder or a behavioural or psychological condition that means they avoid or refuse food.

Malnutrition as a result of a poor diet is rare in the UK, but may occur if a child is neglected, living in poverty or being abused. Call the NSPCC helpline on 0808 800 5000 if you're concerned about a child.